Electrical connector and liquid crystal display device

ABSTRACT

An electrical connector has a contact held by a housing and an operating member for operating the contact. The housing includes an insertion recess into which a shaft-like terminal is inserted along a first direction. A pair of elastic pieces of the contact respectively include clamp portions for clipping the terminal in predetermined clamping directions orthogonal to the first direction. The first direction is along a radial direction of the terminal. The operating member includes a widening operating portion for widening the distance between the clamp portions of the pair of elastic pieces.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an electrical connector which isconnected to a fluorescent tube for a backlight of a liquid crystaldisplay device, etc., and a liquid crystal display device including thesame.

2. Description of Related Arts

For example, as a connecting structure of a terminal of a fluorescenttube such as a cold cathode fluorescent tube to be used as a backlightof a liquid crystal display type television or monitor, the followingdocuments 1 and 2 have been proposed:

Document 1: Japanese Unexamined Patent Publication No. 2001-250605 (dateof publication: Sep. 14, 2001)

Document 2: Japanese Unexamined Patent Publication No. 2004-259645 (dateof publication: Sep. 16, 2004)

In the documents 1 and 2, a connection fitting fixed to one end of anelectric wire is soldered to a terminal (electrode) of a cold cathodefluorescent tube. The other end of the electric wire is connected to aninverter circuit via a connector. Electric power from the invertercircuit is supplied to the cold cathode fluorescent tube via theconnector and the electric wire.

However, in the documents 1 and 2, a continuity failure may occurbetween the terminal and the connection fitting due to defectivesoldering. In addition, the soldering is troublesome. In particular, thecold cathode fluorescent tube has a thin shape with a diameter ofseveral millimeters, and the terminal is thinner than this, so thathandling of these requires great care. Therefore, enormous labor isrequired for soldering.

Not only the case of using a cold cathode fluorescent tube but alsocases of using other fluorescent tubes such as an external electrodefluorescent tube or using a shaft-like terminal other than thefluorescent tubes also have a similar problem.

An object of the present invention is to provide an electrical connectorthat realizes reliable and easy connection of a shaft-like terminal anda liquid crystal display device including the same.

SUMMARY OF THE INVENTION

According to a preferred mode of the present invention, an electricalconnector includes an insulating housing, a contact held by the housing,and an operating member for operating the contact. The housing includesan insertion recess in which a shaft-like terminal is inserted in apredetermined inserting direction. The contact includes a pair ofelastic pieces facing each other. At least a part of the pair of elasticpieces is exposed to the insertion recess. The pair of elastic piecesrespectively have clamp portions for clamping the terminal inpredetermined clamping directions substantially orthogonal to thepredetermined inserting direction. The predetermined inserting directionis along a first diameter direction of the terminal, and thepredetermined clamping directions are in a second diameter direction ofthe terminal. The operating member includes a widening operating portionfor widening the distance between the clamp portions of the pair ofelastic pieces.

According to this mode, while the distance between the clamp portions ofthe pair of elastic pieces of the contact are widened by the wideningoperating portion of the operating member, the terminal can be readilyinserted between the clamp portions in their diameter directions. Next,by releasing the widening operation by the widening operating portion,the terminal is elastically clamped between the clamp portions. Thereby,a predetermined contact pressure is generated between the contact andthe terminal, and as a result, electrical connection between the contactand the terminal can be reliably performed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic sectional view showing a general construction of aliquid crystal display device including an electrical connectoraccording to an embodiment of the present invention;

FIG. 2 is an exploded perspective view of a main part of FIG. 1;

FIG. 3 is a perspective view of an electrical connector;

FIG. 4 is a perspective view of a housing for the electrical connector;

FIG. 5 is a perspective view of a contact;

FIG. 6 is a plan view of the contact observed along a second direction;

FIG. 7 is a sectional view along the VII-VII line of FIG. 6;

FIG. 8 is a sectional view of the main part along the VIII-VIII line ofFIG. 2, illustrating a state that the contact is widened;

FIG. 9 is a sectional view of the main part along the VIII-VIII line ofFIG. 2, illustrating a state that the widening of the contact isreleased;

FIG. 10 is a sectional view along the X-X line of FIG. 8;

FIG. 11 is a sectional view along the XI-XI line of FIG. 9;

FIG. 12 is a perspective view of an operating member;

FIG. 13 is a perspective view of a main part of another embodiment ofthe present invention;

FIG. 14 is a perspective view of a main part of still another embodimentof the present invention;

FIG. 15 is a sectional view of a main part of still another embodimentof the present invention; and

FIG. 16 is a sectional view of a main part of still another embodimentof the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

A preferred embodiment of the present invention will be described withreference to the accompanying drawings.

FIG. 1 is a schematic sectional view showing a general construction of aliquid crystal display device including an electrical connectoraccording to an embodiment of the present invention. Referring to FIG.1, the liquid crystal display device 1 is used as, for example, amonitor of a television or a personal computer.

The liquid crystal display device 1 includes a casing 2, a liquidcrystal panel 3, a circuit board 4 disposed in the rear of the liquidcrystal panel 3, a plurality of cold cathode fluorescent tubes 5 asfluorescent tubes, electrical connectors 6 (hereinafter, simply referredto as connectors), and an inverter circuit 7.

The liquid crystal panel 3 is a non light-emitting display panel, and isattached to an opening on the front of the casing 2. The front face 3 aof the liquid crystal panel 3 faces forward of the casing 2, and theback face 3 b thereof faces rearward of the casing 2.

The circuit board 4 is a plate-shaped member disposed parallel to theliquid crystal panel 3 and fixed to the casing 2, and includes a firstsurface 4 a facing the back face 3 b of the liquid crystal panel 3 and asecond surface 4 b on the opposite side of the first surface 4 a.

The cold cathode fluorescent tubes 5 serve as a backlight of the liquidcrystal panel 3, and are disposed between the back face 3 b of theliquid crystal panel 3 and the first surface 4 a of the circuit board 4.The number of cold cathode fluorescent tubes 5 is, for example, two per1 inch of the liquid crystal panel 3.

As shown in FIG. 2, the longitudinal direction L of each cold cathodefluorescent tube 5 is along the direction X (corresponding to the leftand right direction of the casing 2: the direction perpendicular to thesheet surface in FIG. 1). Referring to FIG. 1, the respective coldcathode fluorescent tubes 5 are disposed at predetermined intervalsalong the direction Y (corresponding to the vertical direction of thecasing 2). The cold cathode fluorescent tubes 5 each are parallel to theback face 3 b of the liquid crystal panel 3. The respective cold cathodefluorescent tubes 5 and the liquid crystal panel 3 are spaced at apredetermined distance in the direction Z (corresponding to the lateraldirection of the casing 2). Each cold cathode fluorescent tube 5irradiates the liquid crystal panel 3 with light from the rear side.

The electrical connector 6 is for realizing electrical connectionbetween the cold cathode fluorescent tubes 5 and the circuit board 4(and eventually the inverter circuit 7). This connector 6 is attached toeach of the pair of ends of each cold cathode fluorescent tube 5 betweenthe back face 3 b of the liquid crystal panel 3 and the first surface 4a of the circuit board 4.

The inverter circuit 7 performs a function to supply driving power tothe cold cathode fluorescent tubes 5, and is attached to the secondsurface 4 b of the circuit board 4. The inverter circuit 7 and therespective cold cathode fluorescent tubes 5 are electrically connectedto each other via the circuit board 4 and corresponding connectors 6.

FIG. 2 is an exploded perspective view of a main part of FIG. 1. FIG. 3is a perspective view of the connector 6.

The attaching structures of the respective cold cathode fluorescenttubes 5 are the same, so the attaching structure of one cold cathodefluorescent tube 5 will be mainly described below.

Referring to FIG. 2, the cold cathode fluorescent tube 5 includes acylindrical main body 8 extending straight along the direction X, andouter leads 10 and 10 (electrodes) as a pair of terminals provided on apair of end portions 9 and 9 of the main body 8, respectively. The outerleads 10 as terminals project along the longitudinal direction L fromthe corresponding end portions 9 of the main body 8.

The main body 8 is a member made of, for example, glass with a diameterof several millimeters through several tens of millimeters. The pair ofouter leads 10 are metal-made shaft-like conductive members made of softiron, etc., and are exposed in the direction X from the respectivecorresponding end portions 9. These outer leads 10 have a diameter of,for example, approximately 1 millimeter and a length of severalmillimeters.

A clamping member 11 is provided for holding the cold cathodefluorescent tube 5 and supporting the weight of the cold cathodefluorescent tube 5. One or a plurality (one in this embodiment) ofclamping members 11 are provided for each cold cathode fluorescent tube5. The number of clamping members 11 is properly determined according tothe length of the cold cathode fluorescent tube 5. The clamping member11 is arranged at a middle portion of the main body 8 of the coldcathode fluorescent tube 5.

This clamping member 11 is, for example, a synthetic resin molded item,and includes a support column 12 and an arced holder 13. The supportcolumn 12 is fixed to the first surface 4 a of the circuit board 4 andextends in the direction Z. The holder 13 holds the middle portion ofthe main body 8 of the cold cathode fluorescent tube 5 while restrainingradial (in the directions Y and Z in FIG. 2) movements of the coldcathode fluorescent tube 5.

This holder 13 is in an arced shape that can surround a part slightlylonger than a peripheral half of the main body 8 of the cold cathodefluorescent tube 5. In a part in the peripheral direction of the holder13, an opening 13 a into which the main body 8 of the cold cathodefluorescent tube 5 is inserted is formed.

Into the opening 13 a, the middle portion in the longitudinal directionL of the main body 8 of the cold cathode fluorescent tube 5 is insertedand held along a first direction D1 that is an attaching direction ofthe cold cathode fluorescent tube 5 to the connectors 6. The opening 13a is open to a second direction D2 (corresponding to a removingdirection of the cold cathode fluorescent tube 5 from the connectors 6)opposite the first direction D1.

As described above, the connector 6 is provided on the pair of endportions 9 and 9, respectively, of the main body 8 of the cold cathodefluorescent tube 5. The constructions of the connectors 6 are the same,so that one connector 6 will be mainly described below.

Referring to FIG. 3, the connector 6 has lengths of 10 through 15millimeters in the directions X, Y, and Z, respectively, and includes ahousing 14, a contact 15 held by this housing 14, and an operatingmember 16 for operating this contact 15.

FIG. 4 is a perspective view of the housing 14. Referring to FIG. 2 andFIG. 4, the housing 14 is an integrally molded item made of a syntheticresin, and has a main body 17 and seating portions 18 extended from themain body 17.

The main body 17 is generally shaped into a box. In the circuit board 4,a through hole is formed at a place where the connector 6 is disposed,and through this through hole, the main body 17 projects from the firstsurface 4 a to the back face 3 b (see FIG. 1) of the liquid crystalpanel 3.

Referring to FIG. 2 and FIG. 4 again, at an end portion of the main body17 in the second direction D2, an introducing groove 19 having aU-shaped or a groove-shaped section is formed. Into the introducinggroove 19, a corresponding end portion 9 of the cold cathode fluorescenttube 5 is introduced. The end portion 9 of the cold cathode fluorescenttube 5 introduced into the introducing groove 19 is protected by beingsurrounded by the inner surface of the introducing groove 19.

At the end portion in the second direction D2 of the main body 17, aninsertion recess 20 is provided. Into the insertion recess 20, an outerlead 10 as a terminal of the cold cathode fluorescent tube 5 is insertedin the first direction D1 as the attaching direction.

The insertion recess 20 is demarcated by a peripheral wall 21 and abottom wall 22 and has a rectangular section, and functions as areceiving cavity for receiving the outer lead 10. The peripheral wall 21includes a pair of first side portions 23 a and 23 b facing each otherin the direction X and a pair of second side portions 24 a and 24 bfacing each other in the direction Y.

One first side portion 23 a is adjacent to the introducing groove 19,and divides between the introducing groove 19 and the insertion recess20. In the first side portion 23 a, at the center in the direction Y, anotched groove 25 is provided. Through the notched groove 25, acorresponding outer lead 10 can be inserted.

Although not shown, the bottom of the notched groove 25 functions as astopper to prevent the outer lead 10 from being shifted although this isnot shown. That is, when the outer lead 10 tilts at a predeterminedangle with respect to the housing 14, the outer lead 10 is received bythe bottom of the notched groove 25 so as not to tilt more.

The phrase “the outer lead 10 tilts with respect to the housing 14”means at least one of a state that the entirety (the main body 8 and theouter lead 10) of the cold cathode fluorescent tube 5 tilts with respectto the housing 14 (circuit board 4) and a state that the main body 8 ofthe cold cathode fluorescent tube 5 does not tilt with respect to thehousing 14 (parallel to the circuit board 4) and the outer lead 10 tiltswith respect to the main body 8.

The other first side portion 23 b is provided with a guide portion 26for guiding the operating member 16 along the first and seconddirections D1 and D2 (direction Z). This guide portion 26 is of a convexshape disposed on the inner side surface of the other first side portion23 b, and extends in the direction Z.

In the pair of second side portions 24 a and 24 b, through holes 27 arerespectively formed. The respective through holes 27 extend along thedirection Z. Into the through holes 27, first and second convex portions53 and 58 described later of the operating member 16 are inserted.

The seating portions 18 are a pair of flange portions provided on theend portion 17 a of the main body 17 in the first direction D1. Theseating portions 18 are respectively disposed on the pair of endportions of the main portion 17 in the direction Y and longitudinallyextend in the direction X. The respective seating portions 18 are incontact with and received by the second surface 4 b of the circuit board4. Thereby, the position of the housing 14 in the direction Z withrespect to the circuit board 4 is determined.

FIG. 5 is a perspective view of the contact 15. FIG. 6 is a plan view ofthe connector 6 observed along the second direction D2. FIG. 7 is asectional view along the VII-VII line of FIG. 6. FIG. 8 is a sectionalview of the main part along the VIII-VIII line of FIG. 2, showing astate that the contact 15 is widened. FIG. 9 is a sectional view of themain part along the VIII-VIII line of FIG. 2, showing a state that thewidening of the contact 15 is released. FIG. 10 is a sectional viewalong the X-X line of FIG. 8. FIG. 11 is a sectional view along theXI-XI line of FIG. 9.

Referring to FIG. 2 and FIG. 5, the contact 15 is a conductive membermade of a metal, etc. In detail, the contact 15 is a sheet metal member.The contact 15 makes electrical connection to the outer lead 10 of thecold cathode fluorescent tube 5. By the contact 15, electricalconnection between the outer lead 10 and the circuit board 4 isrealized.

The contact 15 is symmetrical to the direction Y, and has a main body28, a lead 29, and a pair of elastic pieces 30 and 31 facing each other.

The main body 28 longitudinally extends in the direction Z, and has aU-shaped section orthogonal to the direction Z. The U shaped pairedportions facing each other are formed into flange portions 32. In themain body 28, the section sandwiched by the flange portions 32 isdefined as an intermediate portion 33.

Referring to FIG. 6 and FIG. 7, the main body 28 is press-fitted in andfixed to an insertion hole 34 formed in the main body 17 of the housing14. The insertion hole 34 extends in the direction Z to the insertionrecess 20 from the end portion 17 a in the second direction D2 of themain body 17 of the housing 14. The peripheral surface of the insertionhole 34 surrounds the main body 28 of the contact 15.

On the peripheral surface of the insertion hole 34, a pair of engaginggrooves 35 and 35 that engage with the pair of flange portions 32 arerespectively formed. The engaging grooves 35 extend in the direction Z,and along the engaging grooves 35, the main body 28 of the contact 15can be inserted.

The main body 28 of the contact 15 is received by one end portion of onefirst side portion 23 a of the peripheral wall 21, and the positionthereof in the direction Z with respect to the housing 14 is determined.It is allowed that the main body 28 of the contact 15 is not received bythe one first side portion 23 a of the peripheral wall 21 of the housing14. In this case, according to the insertion amount of the main body 28into the insertion hole 34, the position of the contact 15 in thedirection Z is determined.

Referring to FIG. 5 and FIG. 7, the lead 29 comes into contact with thesecond surface 4 b of the circuit board 4 and realizes electricalconnection between the circuit board 4 and the contact 15. This lead 29is provided on one end portion of the main body 8 and extends to oneside of the direction X from the main body 28. The lead 29 and thesecond surface 4 b of the circuit board 4 are parallel to each other,and are in contact with each other. The lead 29 is soldered to thecircuit board 4 and connected to the inverter circuit 7 via the circuitboard 4. A metal-made reinforcing member 70 provided on the end portion17 a in the second direction D2 of the main body 17 of the housing 14 isfixed to the second surface 4 b of the circuit board 4.

Referring to FIG. 2 and FIG. 8, a pair of elastic pieces 30 and 31realize electrical connection to corresponding outer leads 10,respectively. The pair of elastic pieces 30 and 31 face each other inthe direction Y. The pair of elastic pieces 30 and 31 are respectivelydisposed on the second direction D2 side with respect to thecorresponding flange portions 32 and project to the insertion recess 20,and are almost entirely exposed to the insertion recess 20. It is alsopossible that only a part of the pair of elastic pieces 30 and 31 isexposed to the insertion recess 20.

Each of the pair of elastic pieces 30 and 31 includes a first piece 36extending along the second direction D2 and a second piece 37 that isfolded back from a tip end portion 36 b of the corresponding first piece36 and extends along the first direction D1. The pair of first pieces 36are disposed relatively distant from each other in the direction Y, andthe pair of second pieces 37 are disposed relatively close to eachother.

Each first piece 36 extends along the second direction D2 from a tip endportion in the second direction D2 of the corresponding flange portion32, and penetrates the bottom wall 22 of the insertion recess 20 of thehousing 14. The pair of elastic pieces 30 and 31 can be made elasticallyclose or separated from each other around fulcrums at base end portions36 a of the respective first pieces 36. In a free state (with noexternal force applied), the respective first pieces 36 are arrangedparallel to each other. At a tip end portion 36 b of the respectivefirst pieces 36, an engaging portion 42 to engage with a wideningoperating portion 48 described later is provided. Each engaging portion42 is formed by a small piece projecting to one side of the direction Xfrom the tip end portion 36 b of the corresponding first piece 36.

Referring to FIG. 2 and FIG. 5, each second piece 37 includes a foldedback portion 38 continued to the tip end portion 36 b of thecorresponding first piece 36, a first narrowing portion 39, a straightclamp portion 40 for clipping the outer lead 10 in a predeterminedclamping direction D3 (corresponding to a radial direction of the outerlead 10), a second narrowing portion 41, and a tip end portion 430. Theclamp portion 40 extends straight along the first direction D1.

On one-side surfaces (outer side surfaces) of the pair of folded backportions 38, guide portions 43 for guiding the attaching of the outerlead 10 are respectively provided (only one guide portion 43 is shown inFIG. 5). The pair of guide portions 43 narrow their distance toward thefirst direction D1.

The pair of first narrowing portions 39 are for preventing thecorresponding outer lead 10 from improperly coming off in the seconddirection D2 from the pair of clamp portions 40. The pair of firstnarrowing portions 39 are provided on the tip ends in the firstdirection D1 of the pair of folded back portions 38. In other words,they are provided on the opposite side of the pair of clamp portions 40in the first direction D1.

The distance between the pair of first narrowing portions 39 is madenarrower than the distance between the pair of guide portions 43, andmade narrower than the distance between the pair of clamp portions 40.When the pair of elastic pieces 30 and 31 are made close to each other,the distance between the pair of first narrowing portions 39 becomesnarrower than the diameter of the outer lead 10.

The pair of clamp portions 40 are for allowing relative movements of thecorresponding outer lead 10 in the first and second directions D1 and D2(direction Z) while realizing electrical connection between thecorresponding outer lead 10 and the contact 15. The respective clampportions 40 are provided on the first direction D1 side of thecorresponding first narrowing portions 39. The respective clamp portions40 extend along the direction Z (first direction D1) in a free state,and face parallely to each other.

Referring to FIG. 11, in each clamp portion 40, a portion in contactwith the outer lead 10 forms a contact portion 44 between the back face3 b of the liquid crystal panel 3 and the first surface 4 a (see FIG. 1)of the circuit board 4. A pair of contact portions 44 face each other inthe direction Y, and elastically clip the outer lead 10 therebetween.

Referring to FIG. 2 and FIG. 5 again, the pair of second narrowingportions 41 are for preventing the corresponding outer lead 10 fromimproperly coming off from the pair of clamp portions 40 toward thefirst direction D1. The pair of second narrowing portions 41 areprovided on the first direction D1 side of the pair of clamp portions40.

The distance between the air of second narrowing portions 41 is setnarrower than the distance between the pair of clamp portions 40. Whenthe pair of elastic pieces 30 and 31 come close to each other, thedistance between the pair of second narrowing portions 41 becomesnarrower than the diameter of the outer lead 10.

The respective tip end portions 430 are provided on the first directionD1 side of the corresponding second narrowing portions 41. These tip endportions 430 are for narrowing the distance between the pair of clampportions 40 by being pressed by the first pieces 36. Thereby, the forcefor clipping the outer lead 10 by the pair of clamp portions 40 can beincreased. In addition, lowering in the clipping force due to settlingof the pair of elastic pieces 30 and 31 can be prevented.

The pair of tip end portions 430 are in an inverted V shape when theyare observed along the direction X, and the distance therebetweenexpands toward the first direction D1. On the tip ends in the firstdirection D1 of the respective tip end portions 430, bent portions thatare bent in directions approaching each other are provided so as tosmoothly engage with the corresponding first pieces 36.

Referring to FIG. 2 and FIG. 8, the operating member 16 is forperforming operations of clipping and releasing the clipping of theouter lead 10 by the pair of clamp portions 40, and are relativelymovably fitted in the insertion recess 20 of the housing 14 in the firstand second directions D1 and D2. In FIG. 8, the operating member 16 at awidening position is illustrated, and in FIG. 9, the operating member 16at a widening released position is illustrated.

FIG. 12 is a perspective view of the operating member 16. Referring toFIG. 8 and FIG. 12, the operating member 16 is a resin molded itemformed symmetrically with respect to the direction Y. A sectionorthogonal to the direction Z of the operating member 16 is in a grooveshape.

The operating member 16 has a pair of portions 45 and 46 facing eachother at a distance in the direction Y, a joint 47 that joins the pairof portions 45 and 46, and a pair of widening operating portions 48provided on the joint 47.

The pair of portions 45 and 46 are disposed on both sides across thepair of elastic pieces 30 and 31 in the insertion recess 20. One portion45 is disposed between one elastic piece 30 and the other second sideportion 24 b of the peripheral wall 21. The other portion 46 is disposedbetween the other elastic piece 31 and one second side portion 24 a ofthe peripheral wall 21. The pair of portions 45 and 46 respectivelyextend in the direction Z.

The tip ends on the second direction D2 side of outer side surfaces 49of the pair of portions 45 and 46 (only one outer side surface 49 isshown in FIG. 8 and FIG. 12) project outward of the direction Y withrespect to a peripheral edge 50 of the opening of the insertion recess20, and these projecting portions serve as knobs 51. An operator canoperate the operating member 16 in the first and second directions D1and D2 by pinching the knobs 51.

In the pair of outer side surfaces 49, portions where the knobs 51 arenot provided are formed into clamp portions 52 extending in thedirection Z. On the respective clamp portions 52, first convex portions53 are provided. The pair of first convex portions 53 are for preventingthe operating member 16 from improperly coming off from the insertionrecess 20, and are disposed on the tip ends in the first direction D1 ofthe respective clamp portions 52.

The first convex portions 53 are fitted in corresponding through holes27 of the peripheral wall 21, and they are received by the peripheraledges of the corresponding through holes 27 to prevent the operatingmember 16 from coming off from the insertion recess 20.

The tip ends on the first direction D1 side of the first convex portions53 are formed into inclined shapes. Thereby, when the operating member16 is fitted in the insertion recess 20, these inclined portions allowinsertion of the first convex portions 53 into the corresponding throughholes 27 while smoothly engaging with the peripheral edge 50 of theopening of the peripheral wall 21.

Referring to FIG. 8 and FIG. 9, the connector 6 is provided with firstand second holding mechanisms 55 and 56.

The first holding mechanism 55 holds the operating member 16 at awidening position shown in FIG. 8. Referring to FIG. 8 and FIG. 12, thefirst holding mechanism 55 includes first concave portions 54 providedon the respective clamp portions 52 of the operating member 16, andengaging portions 57 that are respectively provided on the pair ofsecond side portions 24 of the peripheral wall 21 and engage withcorresponding first concave portions 54.

The first concave portion 54 is demarcated between the first convexportion 53 and the second convex portion 58. The second convex portions58 are provided on the respective clamp portions 52 and arranged side byside with corresponding first convex portions 53 along the seconddirection D2. The engaging portions 57 include the portions disposed onthe second direction D2 side of the through holes 27 on the pair ofsecond side portions 24 of the peripheral wall 21, respectively, and arefitted in the first concave portions 54 when the operating member 16 isat the widening position shown in FIG. 8.

Referring to FIG. 9 and FIG. 12, the second holding mechanism 56 holdsthe operating member 16 at a widening released position shown in FIG. 9and FIG. 11. The second holding mechanism 56 includes second concaveportions 59 provided on the respective clamp portions 52 of theoperating member 16 and the engaging portions 57 that are provided onthe pair of second side portions 24 of the peripheral wall 21,respectively, and engage with corresponding second concave portions 59.That is, the engaging portions 57 form apart of the first holdingmechanism 55 and a part of the second holding mechanism 56.

The second concave portions 59 are demarcated between the second convexportions 58 and stepped portions 60 of the respective knobs 51 facingthe peripheral wall 21 side. The engaging portions 57 are fitted in thesecond concave portions 59 when the operating member 16 is at thewidening released position shown in FIG. 9.

Inner side surfaces 61 of the pair of portions 45 and 46 face each otherat a predetermined distance in the direction Y and sandwich the pair ofelastic pieces 30 and 31 of the contact 15. The tip ends in the seconddirection D2 of these inner side surfaces 61 of the pair of portions 45and 46 are formed into inclined cam surfaces, and the distancetherebetween narrows toward the second direction D2.

By the inclined cam surfaces, pressurizing portions 62 are formed. Thepair of pressurizing portions 62 can pressurize pressurized portions 63provided on the tip end portions 36 b of corresponding first pieces 36of the pair of elastic pieces 30 and 31. When the operating member 16 isat the widening released position shown in FIG. 9, the pair ofpressurizing portions 62 come into contact with and pressurize thecorresponding pressurized portions 63, thereby the distance between thepair of clamp portions 40 is narrowed, and as a result, the force forclipping the outer lead 10 by these clamp portions 40 can be increased.In addition, lowering in the clipping force due to settling of the pairof elastic pieces 30 and 31 can be prevented.

The pair of pressurizing portions 62 come into contact with andpressurize corresponding pressurized portions 63 when the operatingmember 16 shifts from the widening position shown in FIG. 8 to thewidening released position shown in FIG. 9 along the first direction D1.Thereby, the forces for pressurizing the corresponding pressurizedportions 63 in the first direction D1 are converted into forces in thedirection Y orthogonal to the first direction D1. Thereby, the pair ofelastic pieces 30 and 31 come close to each other.

The joint 47 is formed into a plate shape, and joins respective one-sideends of the pair of portions 45 and 46 in the direction X. On the outerside surface 65 of the joint 47, a groove 64 extending in the directionZ is formed, and is fitted in the guide portion 26 of the other firstside portion 23 b of the peripheral wall 21 as shown in FIG. 7.

Referring to FIG. 4 and FIG. 12, in the operating member 16, an externalform of a section of a portion where the knob 51 is not provided cutalong a direction orthogonal to the direction Z is substantiallycoincident with the shape of the peripheral edge 50 of the opening ofthe insertion recess 20 observed from the first direction D1. Thereby,the insertion recess 20 is used as a guide groove for guiding theoperating member 16 to the widening position and the widening releasedposition along the first and second directions D1 and D2.

Referring to FIG. 8 and FIG. 12, by the inner side surface 66 of thejoint 47 and the inner side surfaces 61 of the pair of portions 45 and46, a space 67 (space between the pair of portions 45 and 46) in whichthe pair of elastic pieces 30 and 31 can be accommodated is demarcated.

In this space 67, the tip end in the first direction D1 and the tip endin the second direction D2 are open to the outside, and these openpoints are formed into a pair of open portions 68 and 69. Due to theopen portion 68, the space 67 is open to the second direction D2, andthis enables the space 67 to be observed from the outside. In addition,a corresponding outer lead 10 can be inserted into the space 67 throughthe open portion 68.

The pair of widening operating portions 48 are formed by small piecesprovided on the inner side surface 66 of the joint 47. The pair ofwidening operating portions 48 perform the function to widen thedistance between the clamp portions 40 of the pair of second pieces 37via the pair of first pieces 36 by engaging with corresponding engagingportions 42 of the pair of elastic members 30 and 31. The pair ofwidening operating portions 48 are arranged parallel in the direction X,and are sandwiched between the pair of engaging portions 42.

Each of the pair of widening operating portions 48 has a first inclinedcam surface 71 provided on the tip end in the first direction D1 and asecond inclined cam surface 72 provided on the tip end in the seconddirection D2.

The pair of first inclined cam surfaces 71 perform a function to widenthe distance between the pair of engaging portions 42 when the operatingmember 16 is fitted in the insertion recess 20 along the first directionD1. The distance between the pair of inclined cam surfaces 71 narrowstoward the first direction D1.

The pair of first inclined cam surfaces 71 come into contact withcorresponding engaging portions 42 when the operating member 16 shiftstoward the first direction D1. Thereby, the forces of the operatingmember 16 to press the engaging portions 42 toward the first directionD1 is converted into forces in the direction Y orthogonal to the firstdirection D1 (forces to widen the distance between the pair of engagingportions 42).

The pair of second inclined cam surfaces 72 come into contact withcorresponding engaging portions 42 when the operating member 16 movesalong the second direction D2 and shifts from the widening releasedposition to the widening position, thereby performing the function towiden the distance between the pair of engaging portions 42. Thedistance between the pair of inclined cam surfaces 72 narrows toward thesecond direction D2.

The pair of second inclined cam surfaces 72 come into contact with thecorresponding engaging portions 42 when the operating member 16 shiftsto the widening position. Thereby, the forces of the operating member 16to press the engaging portions 42 toward the second direction D2 areconverted into forces in the direction Y orthogonal to the seconddirection D2 (forces to widen the distance between the pair of engagingportions 42).

Referring to FIG. 11, each widening operating portion 48 includes afirst restricting portion 73. Each first restricting portion 73 is forrestricting the first piece 36 of a corresponding elastic piece 30 or 31from shifting in the direction X (longitudinal direction L of the coldcathode fluorescent tube 5: direction along the axial direction of theouter lead 10) when the operating member 16 is at the widening releasedposition.

When the operating member 16 is at the widening released position shownin FIG. 11, each first restricting portion 73 faces the base end portion36 a of a corresponding first piece 36 and restricts this correspondingfirst piece 36 from moving to one side (deep side of the sheet surfaceof FIG. 11) of the direction X.

In addition, each widening operating portion 48 includes a secondrestricting portion 74. Each second restricting portion 74 is forrestricting the second piece 37 of a corresponding elastic member 30 or31 from shifting in the direction X (direction along the axial directionof the outer lead 10) when the operating member 16 is at the wideningreleased position.

When the operating member 16 is at the widening released position, eachsecond restricting portion 74 faces a tip end portion 430 of thecorresponding second piece 37, and restricts this corresponding secondpiece 37 from moving to one side (deep side of the sheet surface of FIG.11) of the direction X.

Referring to FIG. 8, one first side portion 23 a of the peripheral wall21 includes a third restricting portion 75. The third restrictingportion 75 is for restricting the respective first pieces 36 of the pairof elastic pieces 30 and 31 from shifting in the direction X (directionalong the axial direction of the outer lead 10). The third restrictingportion 75 faces the respective first pieces 36 each other, andrestricts the first pieces 36 from moving to the other side of thedirection X.

Referring to FIG. 10 and FIG. 11, the widening position of the operatingmember 16 is a position for widening the distance between the pair ofclamp portions 40 by the widening operating portions 48 so that theouter lead 10 can be inserted between the pair of clamp portions 40 withno insertion force. The widening released position is a position forreleasing this widening.

Referring to FIG. 10, in the liquid crystal display device having theabove-described general construction, the cold cathode fluorescent tube5 (outer lead 10) is mounted as follows; first, the operating member 16is held at the widening position shown in FIG. 10. The pair of wideningoperating portions 48 of the operating member 16 engages with theengaging portion 42 of the corresponding elastic members 30 and 31, andthe distance between the pair of second pieces 37 is widened. At thistime, the distance between the pair of clamp portions 40 is made widerthan the diameter of the outer lead 10, and the distance between thepair of first narrowing portions 39 is made wider than the diameter ofthe outer lead 10.

In this state, as shown in FIG. 2 and FIG. 10, the corresponding coldcathode fluorescent tube 5 is grasped by hand (not shown), etc., and theouter lead 10 of the cold cathode fluorescent tube 5 is made to face theoperating member 16 in the direction Z. Then, the cold cathodefluorescent tube 5 is moved toward the first direction D1 as theattaching direction and the middle portion of the cold cathodefluorescent tube 5 is fitted in the holder 13 of the clamping member 11.Thereby, the middle portion of the cold cathode fluorescent tube 5 isheld by the clamping member 11, and the corresponding outer lead 10 ofthe cold cathode fluorescent tube 5 is moved into the insertion recess20 as shown by the outline arrow and disposed between the pair of clampportions 40.

Next, the operating member 16 is moved toward the first direction D1 andshifted from the widening position shown in FIG. 10 to the wideningreleased position shown in FIG. 11. Thereby, engagement of the pair ofengaging portions 42 by the pair of widening operating portions 48 isreleased, and as a result, by the elastic forces of the pair of elasticpieces 30 and 31, the pair of clamp portions 40 clip the correspondingouter lead 10 by the contact portions 44. Thereby, electrical connectionbetween the contact 15 and the corresponding outer lead 10 is achieved.The distance between the pair of first and second narrowing portions 39and 41 becomes narrower than the diameter of the corresponding outerlead 10.

In addition, by shifting the operating member 16 to the wideningreleased position, the pair of pressurizing portions 62 pressurize thecorresponding pressurized portions 63 as shown by the arrow F1. Thereby,these pressurized portions 63 are moved in the direction Y so as to comeclose to each other. Thereby, the distance between the pair of firstpieces 36 is narrowed, and as a result, pressurizing forces act on thepair of second pieces 37 so as to narrow the distance between the clampportions 40. Thereby, the force for clipping the corresponding outerlead 10 by the pair of clamp portions 40 is increased.

Furthermore, when the operating member 16 shifts to the wideningreleased position, the base end portions 36 a of the pair of firstpieces 36 press the tip end portions 430 of the corresponding secondpieces 37 as shown by the arrow F2. Thereby, these tip ends 430 aremoved in the direction Y so as to come close to each other. Thereby, thedistance between the pair of tip end portions 430 is narrowed, and as aresult, pressurizing forces act to narrow the distance between the pairof clamp portions 40. Thereby, the force for clipping the outer lead 10by the pair of clamp portions 40 is further increased.

On the other hand, in order to remove the outer lead 10 from the contact15, the operating member 16 is first shifted from the widening releasedposition to the widening position along the second direction D2 as shownin FIG. 10. When the operating member 16 is shifted to the wideningposition, the second inclined cam surfaces 72 of the pair of wideningoperating portions 48 engage with corresponding engaging portions 42 andwiden the distance between the pair of engaging portions 42, andaccordingly, the distance between the pair of clamp portions 40 iswidened. The electrical connection between the pair of clamp portions 40and the corresponding outer lead 10 is released.

Next, as shown in FIG. 2 and FIG. 10, the cold cathode fluorescent tube5 is removed from the holder 13 of the clamping member 11 by graspingthe cold cathode fluorescent tube 5 by hand, etc., and moved toward thesecond direction D2. Thereby, the corresponding outer lead 10 of thecold cathode fluorescent tube 5 passes between the pair of firstnarrowing portions 39 and between the pair of guide portions 43 from thepair of clamp portions 40, and is then extracted from the insertionrecess 20.

As described above, according to this embodiment, the clamp portions 40of the pair of elastic pieces 30 and 31 come into contact with thecorresponding outer lead 10 with a predetermined contact pressure byelastically clipping the outer lead 10. Thereby, electrical connectionbetween the contact 15 and the outer lead 10 can be reliably performed.

Furthermore, by widening the distance between the pair of clamp portions40 by the pair of widening operating portions 48, the correspondingouter lead 10 can be readily inserted between the pair of the clampportions 40 with a little force, and as a result, electrical connectionbetween the connector 6 and the outer lead 10 can be readily performed.

Furthermore, in order to connect the connectors 6 to the respective pairof outer leads 10 of the cold cathode fluorescent tube 5 and attach theconnectors 6 to the circuit board 4, the pair of connectors 6 are singlyattached to the circuit board 4. Thereafter, the pair of outer leads 10of the cold cathode fluorescent tube 5 are inserted into the insertionrecesses 20 of corresponding connectors 6 along the first direction D1so that the pair of outer leads 10 can be clipped between thecorresponding pairs of clamp portions 40. That is, the connectors 6 aresingly attached to the circuit board 4, and thereafter, the connectors 6can be connected to the outer leads 10.

The contact 15 and the corresponding outer lead 10 can be connected by asimple operation of moving the operating member 16 toward the firstdirection D1 to shift from the widening position to the wideningreleased position, so that the connecting operation between the contact15 and the corresponding outer lead 10 can be automated by usingmachinery.

In addition, by widening the distance between the pair of clamp portions40 by shifting the operating member 16 to the widening position, thecorresponding outer lead 10 can be readily inserted between these clampportions 40 with no insertion force. In addition, by releasing thewidening by the pair of widening operating portions 48 by shifting theoperating member 16 to the widening released position after insertingthe outer lead 10, the outer lead 10 can be reliably clipped by theelastic forces of the pair of elastic pieces 30 and 31, thereby furtherreliable electrical connection to the outer lead 10 can be realized.

Furthermore, by folding-back the second pieces 37 of the pair of elasticpieces 30 and 31 from the tip ends 36 b of the corresponding firstpieces 36 so as to extend along the first direction D1, the flexibilityof the second pieces 37 can be increased, and when the outer lead 10 isinserted between the clamp portions 40, an excessive reactive force canbe prevented from acting on the outer lead 10.

Furthermore, by engaging the pair of widening operating portions 48 withthe engaging portions 42 provided on the first pieces 36 ofcorresponding elastic pieces 30 and 31, the distance between the clampportions 40 of the second pieces 37 is widened via the first pieces 36.Thereby, the pair of elastic pieces 30 and 31 are elastically deformedand the distance between the clamp portions 40 can be widened. Incomparison with the case of widening the distance between the clampportions 40 by elastically deforming only one of the pair of elasticpieces 30 and 31, the elastic deformation amount (load) on the elasticpiece to be elastically deformed can be reduced. In addition, the secondpieces 37 are not elastically deformed to widen the distance between theclamp portions 40, so that settling of the second pieces 37 can beprevented.

Furthermore, on the respective pair of widening operating portions 48,inclined cam surfaces 72 that come into contact with correspondingengaging portions 42 are formed. The second inclined cam surfaces 72come into contact with the corresponding engaging portions 42 when theoperating member 16 shifts to the widening position. Thereby, the forceto press the engaging portions 42 toward the second direction D2 isconverted into forces in the direction Y. Thereby, the force to move theoperating member 16 toward the second direction D2 can be converted intoforces to widen the distance between the pair of clamp portions 40. Whenthe operating member 16 is moved, the distance between the pair of clampportions 40 can be reliably widened.

In addition, by providing the first restricting portions 73 on the pairof widening operating portions 48, respectively, the pair of firstpieces 36 can be prevented from improperly moving to one side of thedirection X and being applied with an excessive load. Furthermore, byproviding the third restricting portion 75 on the peripheral wall 21,the pair of first pieces 36 can be prevented from improperly moving tothe other side of the direction X and being applied with an excessiveload.

Furthermore, by providing second restricting portions 74 on the pair ofwidening operating portions 48, respectively, the pair of second pieces37 can be prevented from improperly moving to one side of the directionX and being applied with an excessive load. Furthermore, it can beprevented that these second pieces 37 improperly move to one side of thedirection X and the positions of the outer lead 10 and the correspondingclamp portions 40 deviate from each other.

By providing the pair of pressurizing portions 62 on the operatingmember 16, the forces of the pair of clamp portions 40 to clip the outerlead 10 can be increased, and as a result, further reliable contactbetween the clamp portions 40 and the outer lead 10 can be realized.

Furthermore, by pressurizing the pressurized portions 63 provided on thefirst pieces 36 corresponding to the respective pressurizing portions62, the forces from the respective pressurizing portions 62 are reliablytransmitted to the corresponding pair of elastic pieces 30 and 31. Inaddition, by transmitting the pressurizing forces from the respectivepressurizing portions 62 to the second pieces 37 via the correspondingfirst pieces 36, an excessive pressurizing force can be prevented fromacting on the second pieces 37 (the outer lead 10).

By providing the pressurizing portions 62 on the pair of portions 45 and46 of the operating member 16, respectively, the pair of elastic pieces30 and 31 can be clipped by the pair of pressurizing portions 62, and asa result, the pressurizing forces can be reliably supplied to theseelastic pieces 30 and 31.

Furthermore, the pair of pressurizing portions 62 are formed intoinclined cam surfaces, respectively. These inclined cam surfaces comeinto contact with the corresponding pressurized portions 63 when theoperating member 16 shifts to the widening released position, andthereby, the forces of the respective pressurizing portions 62 topressurize the pressurized portions 63 toward the first direction D1 areconverted into forces in the direction Y. Thereby, the force to move theoperating member 16 to the widening released position C2 can beconverted into forces to narrow the distance between the pair of clampportions 40. When the operating member 16 is moved, the distance betweenthe pair of clamp portions 40 can be reliably narrowed.

In addition, the outer lead 10 that is extremely small in diameter andreadily deformed can be readily inserted between the pair of clampportions 40 with a little force, and as a result, an excessive force canbe prevented from acting on the outer lead 10. The outer lead 10 can beprevented from being damaged.

Furthermore, the operating member 16 is held by the housing 14 in ashiftable manner between the widening position and the widening releasedposition. While the operating member 16 is held by the housing 14, theoperating member 16 can be shifted to the widening position and thewidening released position.

The insertion recess 20 is used as a guide groove. By a simple operationof moving the operating member 16 along the insertion recess 20, theoperating member 16 can be reliably shifted to the widening position andthe widening released position.

Furthermore, the open portion 68 is formed in the operating member 16.Therefore, the space 67 between the pair of portions 45 and 46 can beviewed through the open portion 68. Thereby, it can be readily confirmedwhether the respective clamp portions 40 are in contact with thecorresponding outer lead 10 and whether the pair of pressurizingportions 62 are pressurizing the pair of pressurized portions 63.

By the first holding mechanism 55, the operating member 16 can bereliably held at the widening position.

Furthermore, by the second holding mechanism 56, the operating member 16can be reliably held at the widening released position.

In addition, by disposing the cold cathode fluorescent tubes 5 on thefirst surface 4 a of the circuit board 4 and disposing the invertercircuit 7 on the second surface 4 b of the circuit board 4, thesemembers can be stacked in the thickness direction of the circuit board4. Thereby, the area occupied by the circuit board 4 in the planedirection can be reduced and space-saving thereof can be achieved. Bydisposing the circuit board 4 between the cold cathode fluorescent tube5 and the inverter circuit 7, the circuit board 4 can be used as aninsulating layer between the cold cathode fluorescent tube 5 and theinverter circuit 7.

The present invention is not limited to the contents described in theembodiment given above.

For example, an external electrode fluorescent tube 5A can be usedinstead of the cold cathode fluorescent tube 5 as shown in FIG. 13. Inthis case, an electrode layer 10A as a terminal is covered on therespective peripheral surfaces of a pair of end portions 9A (only oneend portion 9A is shown in FIG. 13) of the external electrodefluorescent tube 5A.

In this case, the electrode layer 10A can be readily inserted betweenthe pair of clamp portions 40 with a little force, and an excessiveforce can be prevented from acting on the electrode layer 10A. Theelectrode layer 10A can be prevented from rubbing against and beingdamaged by the pair of elastic pieces 30 and 31.

The tip end portions 430 of the respective second pieces 37 can beomitted. Furthermore, it is also possible that inclined cam surfacessimilar to the first and second inclined cam surfaces 71 and 72 of thewidening operating portions 48 can be provided on the engaging portions42. In this case, on the widening operating portions 48, surfacesstraight in the direction Z can be provided instead of the first andsecond inclined cam surfaces 71 and 72.

The pair of pressurizing portions 62 and the corresponding pair ofpressurized portions 63 can be omitted. Furthermore, the pair of firstnarrowing portions 39 can be omitted, the pair of second narrowingportions 41 can be omitted, and the pair of guide portions 43 can beomitted. Either one of the pair of widening operating portions 48 can beomitted. Furthermore, inclined cam surfaces similar to the pressurizingportions 62 can be provided on the pressurized portions 63. In thiscase, the pressurizing portions 62 can be formed into surfaces straightin the direction Z.

In addition, instead of the operating member 16, the operating member16A shown in FIG. 14 can be used. The operating member 16A has anopening preventive portion 76 that prevents the space 67 between thepair of portions 45 and 46 from opening to the second direction D2.

The opening preventive portion 76 is integrally formed with the pair ofportions 45 and 46 by using a single member. This opening preventiveportion 76 connects the tip end portions in the second direction D2 ofthe pair of portions 45 and 46 to each other. By providing the openingpreventive portion 76, intrusion of a foreign matter in the space 67between the pair of portions 45 and 46 can be prevented.

By forming the section of the opening preventive portion 76 from atransparent material, the space between the pair of portions 45 and 46can be observed from the outside. It is also possible that the openingpreventive portion 76 is separately formed from the pair of portions 45and 46 and is joined thereto via a hinge mechanism. In this case, thespace between the pair of portions 45 and 46 can be observed by openingthe opening preventive portion 76.

Furthermore, the contact 15A shown in FIG. 15 can be used instead of thecontact 15. On each of the pair of elastic pieces 30A and 31A, the firstpiece 36A itself is provided with an engaging portion 42A. In this case,parts of middle portions of the pair of first pieces 36A swell indirections to approach each other, and these swelling portions serve asthe engaging portions 42A. The widening operating portions 48A aredisposed on the inner sides of the corresponding elastic pieces 30A and31A.

The contact 15B shown in FIG. 16 can be used instead of the contact 15.Each of the pair of elastic pieces 30B and 31B includes a second piece37B extending along the second direction D2, and a first piece 36B thatis folded back from the tip end in the second direction D2 of the secondpiece 37B and extends along the first direction D1. A pair of secondpieces 37B are disposed relatively close to each other, and a pair offirst pieces 36B are disposed relatively distant from each other. On therespective second pieces 37B, clamp portions 40 are disposed.

Furthermore, the first restricting portion 73 can be omitted, the secondrestricting portion 74 can be omitted, and the third restricting portion75 can be omitted. The number of clamping members 11 to be provided forone cold cathode fluorescent tube 5 can be two or more. Furthermore, theconnector 6 can be applied to an edge light type liquid crystal displaydevice.

It is also possible that the connector of the present invention is usedfor connection to a shaft-like terminal of others except for thefluorescent tube. For example, it an be used for connection to aterminal of a multipole cable including a number of twisted wires. Inthe case of the multipole cable, the diameter of the terminal becomesthick, so that a sufficient contact pressure with the contact must besecured. Therefore, the effect of using the connector of the presentinvention which can secure a sufficient contact pressure and can beattached to the contact with no insertion force is significant.

The present invention is described in detail above based on a detailedembodiment, and those skilled in the art who understand the details ofthe description given above will readily conceive alterations,modifications, and equivalents thereof. Therefore, the scope of thepresent invention should be within the range of the claims and theequivalents thereof.

The present application corresponds to Japanese Patent Application No.2005-234794 submitted to the Japanese Patent Office on Aug. 12, 2005,and the entire disclosure of this application is incorporated herein byreference.

1.-21. (canceled)
 22. A method for attaching a fluorescent tube,comprising the steps of: inserting a terminal at an end portion of thefluorescent tube with no insertion force between clamp portions opposedto each other of a pair of elastic pieces of a contact along anattaching direction corresponding to a radial direction of thefluorescent tube; and clamping the terminal, which is inserted betweenthe clamp portions, elastically between the clamp portions, wherein inthe clamping step, the terminal is elastically clamped between the clampportions of the pair of elastic pieces in response to an operation forshifting an operating member for operating the contact in a directionwhich is parallel to the attaching direction and faces the samedirection as the attaching direction.
 23. A method for attaching afluorescent tube according to claim 22, wherein in the clamping step,the terminal is elastically clamped between straight portions as theclamp portions of the pair of elastic pieces.
 24. A method for attachinga fluorescent tube according to claim 22, comprising the step ofwidening a distance between the clamp portions of the pair of elasticpieces before the inserting step.
 25. A method for attaching afluorescent tube according to claim 24, wherein in the widening step,the distance between the clamp portions of the pair of elastic pieces isforcedly widened.
 26. A method for attaching a fluorescent tubeaccording to claim 24, wherein in the widening step, the distancebetween the clamp portions of the pair of elastic pieces is forcedlywidened in response to an operation for shifting a widening operatingportion of the operating member for operating the contact.